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Resolved magnetic-field structure and variability near the event horizon of Sagittarius A*

Johnson, Michael D. and Lamb, James (2015) Resolved magnetic-field structure and variability near the event horizon of Sagittarius A*. Science, 350 (6265). pp. 1242-1245. ISSN 0036-8075.

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Near a black hole, differential rotation of a magnetized accretion disk is thought to produce an instability that amplifies weak magnetic fields, driving accretion and outflow. These magnetic fields would naturally give rise to the observed synchrotron emission in galaxy cores and to the formation of relativistic jets, but no observations to date have been able to resolve the expected horizon-scale magnetic-field structure. We report interferometric observations at 1.3-millimeter wavelength that spatially resolve the linearly polarized emission from the Galactic Center supermassive black hole, Sagittarius A*. We have found evidence for partially ordered magnetic fields near the event horizon, on scales of ~6 Schwarzschild radii, and we have detected and localized the intrahour variability associated with these fields.

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Johnson, Michael D.0000-0002-4120-3029
Additional Information:© 2015 American Association for the Advancement of Science. Received 11 June 2015; accepted 13 October 2015. EHT research is funded by multiple grants from NSF, by NASA, and by the Gordon and Betty Moore Foundation through a grant to S.D. The SMA is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics. The Arizona Radio Observatory is partially supported through the NSF University Radio Observatories program. The James Clerk Maxwell Telescope was operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the UK, the Netherlands Organisation for Scientific Research, and the National Research Council of Canada. Funding for CARMA development and operations was supported by NSF and the CARMA partner universities. We thank Xilinx for equipment donations. A.E.B. receives financial support from the Perimeter Institute for Theoretical Physics and the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant. Research at Perimeter Institute is supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Research and Innovation. J.D. receives support from a Sofja Kovalevskaja award from the Alexander von Humboldt Foundation. M.H. was supported by a Japan Society for the Promotion of Science Grant-in-aid. R.P.J.T. receives support from Netherlands Organisation for Scientific Research. Data used in this paper are available in the supplementary materials.
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
Perimeter Institute for Theoretical PhysicsUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Industry CanadaUNSPECIFIED
Province of Ontario Ministry of Research and InnovationUNSPECIFIED
Alexander von Humboldt FoundationUNSPECIFIED
Japan Society for the Promotion of Science (JSPS)UNSPECIFIED
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)UNSPECIFIED
Issue or Number:6265
Record Number:CaltechAUTHORS:20160106-132807251
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Official Citation:Resolved magnetic-field structure and variability near the event horizon of Sagittarius A* Michael D. Johnson, Vincent L. Fish, Sheperd S. Doeleman, Daniel P. Marrone, Richard L. Plambeck, John F. C. Wardle, Kazunori Akiyama, Keiichi Asada, Christopher Beaudoin, Lindy Blackburn, Ray Blundell, Geoffrey C. Bower, Christiaan Brinkerink, Avery E. Broderick, Roger Cappallo, Andrew A. Chael, Geoffrey B. Crew, Jason Dexter, Matt Dexter, Robert Freund, Per Friberg, Roman Gold, Mark A. Gurwell, Paul T. P. Ho, Mareki Honma, Makoto Inoue, Michael Kosowsky, Thomas P. Krichbaum, James Lamb, Abraham Loeb, Ru-Sen Lu, David MacMahon, Jonathan C. McKinney, James M. Moran, Ramesh Narayan, Rurik A. Primiani, Dimitrios Psaltis, Alan E. E. Rogers, Katherine Rosenfeld, Jason SooHoo, Remo P. J. Tilanus, Michael Titus, Laura Vertatschitsch, Jonathan Weintroub, Melvyn Wright, Ken H. Young, J. Anton Zensus, and Lucy M. Ziurys Science 4 December 2015: 350 (6265), 1242-1245. [DOI:10.1126/science.aac7087]
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:63428
Deposited By: Tony Diaz
Deposited On:07 Jan 2016 01:07
Last Modified:09 Mar 2020 13:18

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